Bulevirtide

Verbatim source wording (UK SPC section 4.2): 'Bulevirtide should be administered once daily (every 24 hours ± 4 hours) by subcutaneous injection as monotherapy or in co-administration with a nucleoside/nucleotide analogue for treatment of underlying hepatitis B virus (HBV) infection. The recommended dose of bulevirtide in adult patients is 2 mg once daily.' INITIATION: 'Treatment should be initiated only by a physician experienced in the treatment of patients with HDV infection.' DURATION: 'The optimal treatment duration is unknown. Treatment should be continued as long as associated with clinical benefit. Consideration to discontinue the treatment should be given in case of sustained (6 months) HBsAg seroconversion or loss of virological and biochemical response.' MISSED DOSES: if less than 4 hours have elapsed since the scheduled time, inject as soon as possible and then return to the usual schedule the following day; if more than 4 hours have elapsed, 'the missed dose should not be administered' and the next injection takes place at the usual time the next day 'without doubling'. ⚠️ US/UK DIVERGENCE — DO NOT 'CORRECT' THE 2 mg FIGURE: the openFDA cross-check in this bundle is the US HEPCLUDEX label (Gilead Sciences, label date 2026-05-22), which recommends 8.5 mg once daily and supplies an 8.5 mg single-dose vial. That is US labelling for a different vial presentation and is NOT the UK/EU regimen; the UK SPC product is a 2 mg vial dosed at 2 mg once daily, and only the UK figure is published here. Some sections of the product information we used were incomplete — check the full SPC.

The SPC doses children by WEIGHT BAND, not by mg/kg, so no per-kg figure exists and none has been invented. Verbatim source wording (UK SPC section 4.2, 'Dosing for paediatric patients using bulevirtide 2 mg powder for solution for injection'), given as body weight / volume of reconstituted solution / bulevirtide daily dose: '10 kg to < 25 kg' — '0.5 ml' — '1 mg'; '25 kg to < 35 kg' — '0.75 ml' — '1.5 mg'; '35 kg and above' — '1 ml' — '2 mg'. The concentration figure of 2 recorded above is mg per ml of the RECONSTITUTED 2 mg vial, read directly from that table (1 ml delivers 2 mg) — confirm it against the reconstitution instructions in section 6.6, which were not retrieved in this bundle. POPULATION: 'The recommended dosage of bulevirtide for paediatric patients 3 years of age and older weighing at least 10 kg with compensated liver disease is based on population pharmacokinetic/pharmacodynamic modelling and simulation'; 'The safety and efficacy of bulevirtide in patients younger than 18 years of age have not been established in clinical studies.' The US label states plainly that 'the safety and effectiveness of HEPCLUDEX in pediatric patients less than 18 years of age have not been established'. Verify against a children's formulary and a specialist paediatric hepatology service before use.